Not able to add foreign key constraint to pivot table - mysql

Question

I am trying to create a pivot table, with foreign keys, this is the migration I have made in Laravel:
public function up()
{
Schema::create('player_position', function (Blueprint $table) {
$table->integer('player_id')->unsigned()->index();
$table->integer('position_id')->unsigned()->index();
$table->foreign('player_id')->references('id')->on('players')->onDelete('cascade');
$table->foreign('position_id')->references('id')->on('positions')->onDelete('cascade');
});
}
But, I get an error:
[Illuminate\Database\QueryException]
SQLSTATE[HY000]: General error: 1215 Cannot add foreign key constraint
(SQL: alter table player_position add constraint
player_position_posi tion_id_foreign foreign key (position_id)
references positions (id) on delete cascade)
[PDOException]
SQLSTATE[HY000]: General error: 1215 Cannot add foreign key constraint
I have read that usually foreign key constraint errors are about not assigning unsigned to fields, or already having records in the DB, but my DB is empty, and I my fields have unsigned, so don't know what is the problem?

Answer 1

SQLSTATE[HY000]: General error: 1215 Cannot add foreign key constraint
For a field to be defined as a foreign key, the referenced parent field must have an index defined on it. And the datatype of both the column and its size must be the same.
I think you are violating some of the above rule.

Answer 2

Remove ->index() method as it creates basic index while you want to add foreign key constraint which references primary key on another table.
$table->integer('player_id')->unsigned();
$table->integer('position_id')->unsigned();
$table->foreign('player_id')->references('id')->on('players')->onDelete('cascade');
$table->foreign('position_id')->references('id')->on('positions')->onDelete('cascade');